Device and method for filling a tank with a fluid product

ABSTRACT

A filler device for filling reservoirs with a fluid, the device having a fluid injector, a filler nozzle connected to the injector, a support for receiving a reservoir, and relative movement device for moving the nozzle towards and away from the support along an axis. The support is coupled to a rotation device for driving the support in rotation and thus causing the reservoir to revolve about the axis.

The present invention relates to a method and to a device for filling a reservoir with a fluid. For this purpose, it is general practice to use devices comprising fluid injector means, a filler nozzle connected to the injector means, support means for receiving the reservoir to be filled, and relative movement means for causing the nozzle to move towards and away from the support means along a determined axis. Filler devices of this kind are used in particular in the fields of perfumery, cosmetics, or indeed pharmacy.

It has already been known for a long time to use injector means associated with a filler nozzle to fill reservoirs with fluid. The nozzle is inserted into the reservoir through its opening and the injector means are put into operation to feed the fluid through the filler nozzle. During filling, the filler nozzle can remain static relative to the reservoir. In a variant, it is also possible to move the filler nozzle inside the reservoir as the filler fills with fluid. Either way, it frequently happens the fluid traps bubbles of air inside the reservoir, particularly when the fluid presents viscosity greater than 30,000 centipoises. This is not wanted, and becomes completely unacceptable when the fluid is particularly fragile. Under such circumstances, it is preferable to perform the filling operation under a vacuum, e.g. placing the reservoir inside an evacuated enclosure fitted with a filler head. Thus, prior to injecting the fluid into the reservoir, the air is evacuated from the enclosure. The fluid can then be filled without any risk of trapping bubbles of air. Once the filling operation has terminated, the reservoir can be returned to atmospheric pressure, or in a variant the enclosure may be provided with a station for mounting a pump or a valve thereon. That vacuum filling technique is particularly effective and gives very good results. Nevertheless, it requires equipment that is expensive and that needs thorough maintenance. That considerably increases the cost of the filling operation, and as a result increases the cost of the fluid dispenser.

Another drawback associated with the vacuum filling technique is the length of time needed to evacuate the enclosure and to restore it to atmospheric pressure. As a result, assembly lines that use such vacuum filler devices are particularly slow, thereby further increasing the cost of the filling operation.

Documents U.S. Pat. No. 5,095,955, DE 19 534 329, and U.S. Pat. No. 4,966,205 describe reservoir filler devices in which the injection rate of the fluid, the speed of rotation of the reservoir, and/or the axial travel speed of the nozzle can be modified. The flow rate and speed values are nevertheless constant during filling. As a result filling is not optimized, particularly at the beginning and at the end of filling.

An object of the present invention is to remedy the above-mentioned drawbacks of the prior art by defining a filler device that is less expensive and faster.

To solve this problem, the present invention proposes a method of filling a reservoir with a fluid, the reservoir having a bottom and an opening, and the method comprising the following successive steps:

-   -   placing the reservoir on a rotary support;     -   inserting an injection nozzle into the reservoir down to the         level of its bottom; and     -   simultaneously injecting the fluid into the reservoir via the         nozzle, causing the rotary support rotate with the reservoir         placed thereon, and raising the nozzle inside the reservoir,         with the speed of rotation, the injection rate, and/or the         upward speed varying during filling of the reservoir. Thus, the         three main parameters of the filling operation, namely the axial         speed of movement of the nozzle, the speed of rotation of the         reservoir, and the injection rate, can be modified in correlated         manner to achieve optimized filling performance. Each parameter         can thus be selected or modified during filling as a function of         various criteria, in particular the viscosity of the fluid. To         achieve the correlation, the filler device also includes         adjustment and control means for adjusting and controlling at         least one parameter selected from the speed of rotation of the         rotation means, the axial speed of the relative movement means,         and the injection rate of the injector means. These adjustment         and control means may for example be in the form of suitable         software that enables optimum values to be determined for the         speeds and the flow rates. For example, the software may         automatically calculate two parameters as a function of a         parameter that is imposed. The three parameters may also be         determined automatically as a function of the viscosity of the         fluid. Other criteria may also be taken into consideration for         determining the values of the parameters, such as, for example,         the diameter of the reservoir and/or its height, and more         generally its shape.

Advantageously, the nozzle has an outlet that remains substantially static relative to the top surface of the fluid in the reservoir while it is being filled. In another aspect, the speed of rotation of the reservoir varies during the filling of the reservoir. As a variant or in addition, the injection rate varies during the filling of the reservoir. The filling method of the invention may also include adjusting in correlated manner the speed of rotation, the upward speed of the nozzle, and/or the injection rate during filling of the reservoir. Under such circumstances, the speed of rotation and the upward speed are greater at the beginning of filling than at the end of filling.

In an advantageous implementation, the filling comprising at least three stages, namely an initial stage of filling the bottom region I of the reservoir, an intermediate stage of filling the drum region II of the reservoir, and a final stage of filling the neck region III of the reservoir, the speed of rotation advantageously being greater in the initial stage than in the final stage, and lower in the initial stage than in the intermediate stage. This implementation is particularly effective with variable-volume reservoirs making use of a follower piston that slides in leaktight manner in a cylindrical drum formed by the body of the reservoir. Such a follower-piston reservoir defines zones that are particularly difficult to fill with a fluid that is viscous. In this implementation, it is guaranteed that these zones are filled completely.

The invention also defines a filler device for filling reservoirs with a fluid, the device comprising fluid injector means, a filler nozzle connected to the injector means, support means for receiving a reservoir, and relative movement means for causing the nozzle to move towards and away from the support means along an axis, the support means being coupled to rotation means for driving the support means in rotation and thus causing the reservoir to revolve about the axis, the device being characterized in that it further comprises adjustment and control means for acting during filling of the reservoir to adjust and control at least one parameter selected from the speed of rotation of the rotation means, the axial speed of the relative movement means, and the injection rate of the injector means.

This eliminates nay risk of trapping bubbles of air in the fluid stored in the reservoir. Advantageously, the movement means are controllable in axial speed to keep the nozzle level with the top surface of the fluid in the reservoir while it is being filled. By causing the reservoir to rotate, the top surface of the fluid inside the reservoir takes up the form of a meniscus that deepens with increasing speed of rotation. Because the reservoir is revolving about the axis X and because the nozzle is movable in axial translation along the axis X, the nozzle is positioned at the center of the meniscus at its lowest point. By practically maintaining contact between the bottom end of the nozzle and the top surface of the fluid, it is guaranteed that the fluid is fed directly into the bulk of fluid that has already been injected into the reservoir. This eliminates any risk of splashing or projections, and the fluid meniscus can thus rise inside the reservoir in a manner that is substantially constant and regular. This serves reliably to avoid forming bubbles of air inside the reservoir.

One of the principles of the invention thus resides in combining raising the nozzle with rotating the reservoir. Another principle resides in causing the upward speed of the nozzle, the speed of rotation of the reservoir, and/or the injection flow rate of the fluid to vary while the reservoir is being filled. Another principle is to cause these three parameters to vary together in correlated manner during filling. It is also possible to cause only two of the three parameters to vary in correlated manner. Nevertheless, a basic principle lies in causing the reservoir to revolve while it is being filled, regardless of whether the nozzle is stationary or movable relative to the reservoir.

The invention is described below in greater detail with reference to the accompanying drawings showing an embodiment of the invention by way of non-limiting examples.

In the figures:

FIG. 1 is a diagrammatic overall view of a filler device of the invention;

FIGS. 2, 3, 4, and 5 show successive filling steps performed in a method of the invention; and

FIG. 6 is a vertical cross-section view through a conventional reservoir with a follower piston for the purpose of explaining the various filling stages of the invention.

Reference is made initially to FIG. 1 to explain in detail the various elements of a filler device of the invention. The filler device comprises injector means 2, an injection nozzle 3, axial movement means 4, rotary support means 5, rotation means 6, and adjustment and control means 7. Naturally, the device may have further elements in order to enable it to operate properly or to perform additional functions.

The filler nozzle 3 comprises a filler spout 31 connected to a head 32. The filler spout 31 is terminated by a delivery outlet 33.

The nozzle 3 is associated with the axial movement means 4 that enable the nozzle to move axially along an axis X. In other words, the nozzle 3 can move down and up.

Furthermore, the nozzle 3 is connected in fluid flow manner to the injector means 2 that enable the fluid to be taken to the nozzle 3 and delivered through its outlet 33.

Furthermore, the support means 5 are coupled to the rotary drive means 6 that serve to make the support means revolve about the axis X.

Consequently, the filler nozzle 3 and the support means 5 both lie on the axis X, the nozzle moving axially along the axis X and the support means revolving about the same axis X. The support means 5 are axially stationary, such that axial movement of the filler nozzle 3 has the effect of moving the nozzle 3 towards or away from the support means 5. In a variant, it is equally possible to imagine the filler nozzle 3 being axially stationary and the support means 5, already driven in rotation about the axis X, also moving axially along said axis away from or towards the nozzle 3. The important characteristic is that there is relative movement between the nozzle and the support means, and it matters little whether one or the other of them moves axially.

The adjustment and control means 7 act simultaneously on the injector means 2, the movement means 4, and the rotation means 6. Nevertheless, it can be imagined that the adjustment and control means act on only one or two of those elements. The adjustment and control means 7 control actuation of the movement means 4 so as to move the filler nozzle 3 axially. In addition, the adjustment and control means act on the movement means to adjust or vary the axial travel speed of the filler nozzle 3. Naturally, the adjustment and control means can thus act to adjust the movement rate of the nozzle 3, i.e. its travel speed and its travel stroke between a top dead center and a bottom dead center.

The adjustment and control means 7 also act on the injector means 2, not only to put the injector means 2 into operation, but also to adjust or vary the rate at which the fluid is injected. Depending on the travel speed of the nozzle 3, it is necessary to adapt or correlate the fluid injection rate generated by the injector means 2. If the axial travel speed of the nozzle 3 is slow, then it is necessary to reduce the fluid injection rate. Conversely, if the travel speed of the nozzle is high, then the injection rate must be increased. Similarly, if the speed of the nozzle 3 varies during a movement of the nozzle, e.g. an upward movement, then it is also necessary to vary the injection rate as the nozzle moves upwards. The adjustment and control means 7 also act on the rotation means 6 not only to cause the rotation means to be put into operation, but also to adjust or vary their speed of rotation. For example, it is possible to imagine that the speed of rotation is higher at the beginning of a filling operation than it is towards the end of the filling operation.

Thus, so to speak, the adjustment and control means 7 constitute, the brain of the filler device serving to adjust and control all of the parameters of the device, namely the speed of rotation, the axial travel speed, and the fluid flow rate. The adjustment and control means 7 serve to correlate all of these parameters for the purpose of obtaining optimum filling performance. By way of example, two or three of these parameters may be determined in correlated manner as a function of determined criteria, e.g. such as the viscosity of the fluid to be injected, the diameter of the reservoir, and its height, and more generally the shape of the reservoir. Account may also be taken of variations in viscosity as a function of temperature or of the fluid being set into motion. It is also possible to determine two parameters as a function of an imposed parameter. By way of example, the adjustment and control means 7 may be in the form of appropriate software run on a computer.

Reference is now made to FIGS. 2, 3, 4, and 5 for explaining in detail one complete operating cycle of the filler device of the invention used in the filling method of the invention.

Initially, the reservoir 1 has a bottom 11 and an opening 12 formed by a neck 13. The reservoir 1 is placed on the support means 5 so as to be axially centered on the axis X. The spout 31 is placed axially above the opening 12, shown in FIG. 1. The first step of the filling method consists in moving the nozzle towards the support means 5 so as to cause the spout 31 to penetrate inside the reservoir through its opening 12. The spout 31 is preferably inserted until the delivery outlet 33 is situated close to or in contact with the bottom 11 of the reservoir 1.

It is then possible to actuate the injector means 2 to as to feed the fluid into the reservoir. Simultaneously, or shortly after or before, the rotation means 6 are actuated to drive the reservoir 1 so that it revolves about the axis X. Simultaneously or very shortly after or before, the movement means 4 are actuated so as to cause the nozzle to move up inside the reservoir. According to an advantageous characteristic of the invention, it is advantageous for the outlet 33 of the spout to track the top surface S of the fluid inside the reservoir. In other words, it is advantageous for the spout 31 to remain in contact with the fluid inside the reservoir. Because the reservoir 1 is rotating, the top surface S of the fluid takes up the shape of a meniscus that is increasingly depressed with increasing speed of rotation of the reservoir. The spout 31 is situated at the center of the meniscus at its lowest point. The outlet 33 can thus be maintained immediately above the lowest point of the meniscus and can track this lowest point as the reservoir is filled progressively.

The filling operation continues as shown in FIG. 3. The reservoir fills and the outlet 33 of the spout tracks the top surface S of the fluid. The filling operation terminates when the spout 31 has no more than its outlet 33 inserted in the opening 12. This is shown in FIG. 4. The nozzle can then be raised finally, rotation 5 can be stopped, and naturally injection is stopped. The reservoir 1 is then filled well and completely with the fluid P, without including the least bubble of air. This can be explained by the fact that the filling operation combined or correlated movement of the nozzle 3, and injection rate, and rotation of the reservoir 1. In order to obtain good filling, it is necessary to vary certain parameters during the filling operation. For example, it is possible to reduce the speed of rotation at the end of filling. It is also possible to reduce the injection rate at the end of filling. This naturally causes the rate at which the nozzle is raised to slow down at the end of filling. It can then readily be understood that it is important and advantageous to correlate all of the parameters by causing them to vary appropriately in order to achieve the intended object, namely good filling without any inclusion of air.

Reference is now made to FIG. 6 to explain in detail an advantageous implementation of the invention for filling a reservoir of variable volume that makes use of a follower piston. The reservoir 1 comprises a cylindrical slide drum 10, a neck 13 defining an opening 12, and a bottom that is shown in the form of a follower piston 11 slidably engaged in leaktight manner inside the slide drum 10. For this purpose, the follower piston 11 comprises a plate 111 defining a central cavity 114 that serves, at the end of the stroke of the follower piston when it comes into the vicinity of the neck, to receive the body of the pump that is fastened in the neck 13. Furthermore, the plate 111 has its outer periphery extended by two annular lips 112 and 113 that are in leaktight sliding contact with the inside of the drum 10. In the initial position prior to filling, the follower piston 11 is in the configuration shown in FIG. 6. The reservoir then defines its maximum working volume. Each time the pump (not shown) is actuated, fluid is extracted from the reservoir, thereby having the effect of sucking up the follower piston 11 that then moves inside the drum 10 in the appropriate direction for reducing the volume of the reservoir. That configuration is entirely conventional for a follower piston reservoir.

All reservoirs are difficult to fill, but a reservoir of this follower-piston type is even more difficult to fill because of the non-level shape of its bottom constituted by the follower piston 11. It is extremely difficult to fill firstly a zone Z1 defined by the cavity 114 and secondly a zone Z2 that extends around the upper lip 113 at the outer periphery of the plate 111. These zones Z1 and Z2, shown in FIG. 6, are specific to follower piston reservoirs. In addition to these zones, the reservoir, like any other reservoir, also defines two other zones Z3 and Z4 that are likewise difficult to fill. The zone Z3 is defined at the top end of the drum at the transition between the drum and the neck 13. The zone Z4 corresponds to the inside of the neck 13.

The filler device and filling method of the invention can be used most effectively for filling such a follower piston reservoir. For this purpose, the reservoir is artificially subdivided into three regions I, II, and III, corresponding respectively to the bottom region of the reservoir, to the drum region of the reservoir, and to the neck region of the reservoir. To achieve good filling of the zones z1, Z2, Z3, and Z4, the speed of rotation of the reservoir, the upward speed of the nozzle, and/or the injection flow rate are caused to vary in appropriate manner from one region to another. Thus, filling comprises at least three stages corresponding to the three regions I, II, and III. For example, the reservoir can be caused to revolve at 1500 revolutions per minute (rpm) in the region I, at 2000 rpm in the region II, and at 500 rpm to 1000 rpm in the region III. The injection flow rate may be kept constant, or on the contrary it may be modulated in a manner that is correlated with the variation in the speed of rotation. The upward travel speed of the nozzle needs to be modified appropriately so as to keep its outlet 33 substantially static relative to the bottom of the meniscus formed by the top surface of the fluid inside the reservoir. Each of these parameters of the device can be determined empirically and/or by successive approximations until optimum filling of the reservoir is obtained. It then suffices to retain the values for the various parameters in a memory incorporated in the adjustment and control means 7. In the above implementation, the parameters may be kept constant within each of the regions I, II, and III. Nevertheless, it is also possible to cause the values of the parameters to vary within any one region, such as for example in the region I or in the region III so as to optimize filling of the zones Z1, Z2, Z3, and Z4.

By means of the invention, it is possible to fill reservoirs with the same quality as can be obtained with a vacuum filler device, merely by combining certain parameters in correlated manner. 

1. A method of filling a reservoir a fluid, the reservoir having a bottom and an opening, and the method comprising the following successive steps: placing the reservoir on a rotary support; inserting an injection nozzle into the reservoir down to the level of its bottom; and simultaneously injecting the fluid into the reservoir via the nozzle, causing the rotary support rotate with the reservoir placed thereon, and raising the nozzle inside the reservoir, with the speed of rotation, the injection rate, and/or the upward speed varying during filling of the reservoir.
 2. A filling method according to claim 1, wherein the nozzle has an outlet that remains substantially static relative to the top surface of the fluid in the reservoir while it is being filled.
 3. A filling method according to claim 1, comprising adjusting in correlated manner the speed of rotation, the upward speed of the nozzle, and/or the injection rate while filling the reservoir.
 4. A filling method according to claim 1, wherein the speed of rotation, the upward speed, and/or the injection rate are determined as a function of the shape of the reservoir to be filled and/or as a function of the fluid to be injected into the reservoir.
 5. A filling method according to claim 1, wherein the speed of rotation and the upward speed are greater at the beginning of filling than at the end of filling.
 6. A filling method according to claim 1, wherein the reservoir comprises a drum, a bottom, and a neck, thereby defining a bottom region I, a drum region II, and a neck region III, the filling comprising at least three stages, namely an initial stage of filling the bottom region I of the reservoir, an intermediate stage of filling the drum region II of the reservoir, and a final stage of filling the neck region III of the reservoir, the speed of rotation advantageously being greater in the initial stage than in the final stage, and lower in the initial stage than in the intermediate stage.
 7. A filler device for filling reservoirs with a fluid, the device comprising fluid injector means, a filler nozzle connected to the injector means, support means for receiving a reservoir, and relative movement means for causing the nozzle to move towards and away from the support means along an axis, the support means being coupled to rotation means for driving the support means in rotation and thus causing the reservoir to revolve about the axis, the device being characterized in that it further comprises adjustment and control means for acting during filling of the reservoir to adjust and control at least one parameter selected from the speed of rotation of the rotation means, the axial speed of the relative movement means, and the injection rate of the injector means.
 8. A filler device according to claim 7, wherein the movement means are controllable in axial speed to keep the nozzle at the level of the top surface of the fluid in the reservoir while it is being filled. 